1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "runtime/atomic.hpp"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/top.hpp"
33 #ifdef TARGET_OS_FAMILY_linux
34 # include "jvm_linux.h"
35 # include <setjmp.h>
36 #endif
37 #ifdef TARGET_OS_FAMILY_solaris
38 # include "jvm_solaris.h"
39 # include <setjmp.h>
40 #endif
41 #ifdef TARGET_OS_FAMILY_windows
42 # include "jvm_windows.h"
43 #endif
44 #ifdef TARGET_OS_FAMILY_aix
45 # include "jvm_aix.h"
46 # include <setjmp.h>
47 #endif
48 #ifdef TARGET_OS_FAMILY_bsd
49 # include "jvm_bsd.h"
50 # include <setjmp.h>
51 # ifdef __APPLE__
52 # include <mach/mach_time.h>
53 # endif
54 #endif
55
56 class AgentLibrary;
57
58 // os defines the interface to operating system; this includes traditional
59 // OS services (time, I/O) as well as other functionality with system-
60 // dependent code.
61
62 typedef void (*dll_func)(...);
63
64 class Thread;
65 class JavaThread;
66 class Event;
67 class DLL;
68 class FileHandle;
69 class NativeCallStack;
70
71 template<class E> class GrowableArray;
72
73 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
74
75 // Platform-independent error return values from OS functions
76 enum OSReturn {
77 OS_OK = 0, // Operation was successful
78 OS_ERR = -1, // Operation failed
79 OS_INTRPT = -2, // Operation was interrupted
80 OS_TIMEOUT = -3, // Operation timed out
81 OS_NOMEM = -5, // Operation failed for lack of memory
82 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
83 };
84
85 enum ThreadPriority { // JLS 20.20.1-3
86 NoPriority = -1, // Initial non-priority value
87 MinPriority = 1, // Minimum priority
88 NormPriority = 5, // Normal (non-daemon) priority
89 NearMaxPriority = 9, // High priority, used for VMThread
90 MaxPriority = 10, // Highest priority, used for WatcherThread
91 // ensures that VMThread doesn't starve profiler
92 CriticalPriority = 11 // Critical thread priority
93 };
94
95 // Executable parameter flag for os::commit_memory() and
96 // os::commit_memory_or_exit().
97 const bool ExecMem = true;
98
99 // Typedef for structured exception handling support
100 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
101
102 class MallocTracker;
103
104 class os: AllStatic {
105 friend class VMStructs;
106 friend class MallocTracker;
107 public:
108 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
109
110 private:
111 static OSThread* _starting_thread;
112 static address _polling_page;
113 static volatile int32_t * _mem_serialize_page;
114 static uintptr_t _serialize_page_mask;
115 public:
116 static size_t _page_sizes[page_sizes_max];
117
118 private:
119 static void init_page_sizes(size_t default_page_size) {
120 _page_sizes[0] = default_page_size;
121 _page_sizes[1] = 0; // sentinel
122 }
123
124 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
125 size_t alignment_hint = 0);
126 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
127 static void pd_split_reserved_memory(char *base, size_t size,
128 size_t split, bool realloc);
129 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
130 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
131 bool executable);
132 // Same as pd_commit_memory() that either succeeds or calls
133 // vm_exit_out_of_memory() with the specified mesg.
134 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
135 bool executable, const char* mesg);
136 static void pd_commit_memory_or_exit(char* addr, size_t size,
137 size_t alignment_hint,
138 bool executable, const char* mesg);
139 static bool pd_uncommit_memory(char* addr, size_t bytes);
140 static bool pd_release_memory(char* addr, size_t bytes);
141
142 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
143 char *addr, size_t bytes, bool read_only = false,
144 bool allow_exec = false);
145 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
146 char *addr, size_t bytes, bool read_only,
147 bool allow_exec);
148 static bool pd_unmap_memory(char *addr, size_t bytes);
149 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
150 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
151
152 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
153
154 static void initialize_initial_active_processor_count();
155 public:
156 static void init(void); // Called before command line parsing
157 static void init_before_ergo(void); // Called after command line parsing
158 // before VM ergonomics processing.
159 static jint init_2(void); // Called after command line parsing
160 // and VM ergonomics processing
161 static void init_globals(void) { // Called from init_globals() in init.cpp
162 init_globals_ext();
163 }
164
165 // File names are case-insensitive on windows only
166 // Override me as needed
167 static int file_name_strcmp(const char* s1, const char* s2);
168
169 // get/unset environment variable
170 static bool getenv(const char* name, char* buffer, int len);
171 static bool unsetenv(const char* name);
172
173 static bool have_special_privileges();
174
175 static jlong javaTimeMillis();
176 static jlong javaTimeNanos();
177 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
178 static void run_periodic_checks();
179
180
181 // Returns the elapsed time in seconds since the vm started.
182 static double elapsedTime();
183
184 // Returns real time in seconds since an arbitrary point
185 // in the past.
186 static bool getTimesSecs(double* process_real_time,
187 double* process_user_time,
188 double* process_system_time);
189
190 // Interface to the performance counter
191 static jlong elapsed_counter();
192 static jlong elapsed_frequency();
193
194 // The "virtual time" of a thread is the amount of time a thread has
195 // actually run. The first function indicates whether the OS supports
196 // this functionality for the current thread, and if so:
197 // * the second enables vtime tracking (if that is required).
198 // * the third tells whether vtime is enabled.
199 // * the fourth returns the elapsed virtual time for the current
200 // thread.
201 static bool supports_vtime();
202 static bool enable_vtime();
203 static bool vtime_enabled();
204 static double elapsedVTime();
205
206 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
207 // It is MT safe, but not async-safe, as reading time zone
208 // information may require a lock on some platforms.
209 static char* local_time_string(char *buf, size_t buflen);
210 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
211 // Fill in buffer with current local time as an ISO-8601 string.
212 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
213 // Returns buffer, or NULL if it failed.
214 static char* iso8601_time(char* buffer, size_t buffer_length);
215
216 // Interface for detecting multiprocessor system
217 static inline bool is_MP() {
218 // During bootstrap if _processor_count is not yet initialized
219 // we claim to be MP as that is safest. If any platform has a
220 // stub generator that might be triggered in this phase and for
221 // which being declared MP when in fact not, is a problem - then
222 // the bootstrap routine for the stub generator needs to check
223 // the processor count directly and leave the bootstrap routine
224 // in place until called after initialization has ocurred.
225 return (_processor_count != 1) || AssumeMP;
226 }
227 static julong available_memory();
228 static julong physical_memory();
229 static bool has_allocatable_memory_limit(julong* limit);
230 static bool is_server_class_machine();
231
232 // number of CPUs
233 static int processor_count() {
234 return _processor_count;
235 }
236 static void set_processor_count(int count) { _processor_count = count; }
237
238 // Returns the number of CPUs this process is currently allowed to run on.
239 // Note that on some OSes this can change dynamically.
240 static int active_processor_count();
241
242 // At startup the number of active CPUs this process is allowed to run on.
243 // This value does not change dynamically. May be different from active_processor_count().
244 static int initial_active_processor_count() {
245 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
246 return _initial_active_processor_count;
247 }
248
249 // Bind processes to processors.
250 // This is a two step procedure:
251 // first you generate a distribution of processes to processors,
252 // then you bind processes according to that distribution.
253 // Compute a distribution for number of processes to processors.
254 // Stores the processor id's into the distribution array argument.
255 // Returns true if it worked, false if it didn't.
256 static bool distribute_processes(uint length, uint* distribution);
257 // Binds the current process to a processor.
258 // Returns true if it worked, false if it didn't.
259 static bool bind_to_processor(uint processor_id);
260
261 // Give a name to the current thread.
262 static void set_native_thread_name(const char *name);
263
264 // Interface for stack banging (predetect possible stack overflow for
265 // exception processing) There are guard pages, and above that shadow
266 // pages for stack overflow checking.
267 static bool uses_stack_guard_pages();
268 static bool allocate_stack_guard_pages();
269 static void bang_stack_shadow_pages();
270 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
271
272 // OS interface to Virtual Memory
273
274 // Return the default page size.
275 static int vm_page_size();
276
277 // Returns the page size to use for a region of memory.
278 // region_size / min_pages will always be greater than or equal to the
279 // returned value. The returned value will divide region_size.
280 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
281
282 // Returns the page size to use for a region of memory.
283 // region_size / min_pages will always be greater than or equal to the
284 // returned value. The returned value might not divide region_size.
285 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
286
287 // Return the largest page size that can be used
288 static size_t max_page_size() {
289 // The _page_sizes array is sorted in descending order.
290 return _page_sizes[0];
291 }
292
293 // Methods for tracing page sizes returned by the above method; enabled by
294 // TracePageSizes. The region_{min,max}_size parameters should be the values
295 // passed to page_size_for_region() and page_size should be the result of that
296 // call. The (optional) base and size parameters should come from the
297 // ReservedSpace base() and size() methods.
298 static void trace_page_sizes(const char* str, const size_t* page_sizes,
299 int count) PRODUCT_RETURN;
300 static void trace_page_sizes(const char* str, const size_t region_min_size,
301 const size_t region_max_size,
302 const size_t page_size,
303 const char* base = NULL,
304 const size_t size = 0) PRODUCT_RETURN;
305
306 static int vm_allocation_granularity();
307 static char* reserve_memory(size_t bytes, char* addr = 0,
308 size_t alignment_hint = 0);
309 static char* reserve_memory(size_t bytes, char* addr,
310 size_t alignment_hint, MEMFLAGS flags);
311 static char* reserve_memory_aligned(size_t size, size_t alignment);
312 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
313 static void split_reserved_memory(char *base, size_t size,
314 size_t split, bool realloc);
315 static bool commit_memory(char* addr, size_t bytes, bool executable);
316 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
317 bool executable);
318 // Same as commit_memory() that either succeeds or calls
319 // vm_exit_out_of_memory() with the specified mesg.
320 static void commit_memory_or_exit(char* addr, size_t bytes,
321 bool executable, const char* mesg);
322 static void commit_memory_or_exit(char* addr, size_t size,
323 size_t alignment_hint,
324 bool executable, const char* mesg);
325 static bool uncommit_memory(char* addr, size_t bytes);
326 static bool release_memory(char* addr, size_t bytes);
327
328 // Touch memory pages that cover the memory range from start to end (exclusive)
329 // to make the OS back the memory range with actual memory.
330 // Current implementation may not touch the last page if unaligned addresses
331 // are passed.
332 static void pretouch_memory(char* start, char* end);
333
334 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
335 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
336 bool is_committed = true);
337
338 static bool guard_memory(char* addr, size_t bytes);
339 static bool unguard_memory(char* addr, size_t bytes);
340 static bool create_stack_guard_pages(char* addr, size_t bytes);
341 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
342 static bool remove_stack_guard_pages(char* addr, size_t bytes);
343
344 static char* map_memory(int fd, const char* file_name, size_t file_offset,
345 char *addr, size_t bytes, bool read_only = false,
346 bool allow_exec = false);
347 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
348 char *addr, size_t bytes, bool read_only,
349 bool allow_exec);
350 static bool unmap_memory(char *addr, size_t bytes);
351 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
352 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
353
354 // NUMA-specific interface
355 static bool numa_has_static_binding();
356 static bool numa_has_group_homing();
357 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
358 static void numa_make_global(char *addr, size_t bytes);
359 static size_t numa_get_groups_num();
360 static size_t numa_get_leaf_groups(int *ids, size_t size);
361 static bool numa_topology_changed();
362 static int numa_get_group_id();
363
364 // Page manipulation
365 struct page_info {
366 size_t size;
367 int lgrp_id;
368 };
369 static bool get_page_info(char *start, page_info* info);
370 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
371
372 static char* non_memory_address_word();
373 // reserve, commit and pin the entire memory region
374 static char* reserve_memory_special(size_t size, size_t alignment,
375 char* addr, bool executable);
376 static bool release_memory_special(char* addr, size_t bytes);
377 static void large_page_init();
378 static size_t large_page_size();
379 static bool can_commit_large_page_memory();
380 static bool can_execute_large_page_memory();
381
382 // OS interface to polling page
383 static address get_polling_page() { return _polling_page; }
384 static void set_polling_page(address page) { _polling_page = page; }
385 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
386 static void make_polling_page_unreadable();
387 static void make_polling_page_readable();
388
389 // Routines used to serialize the thread state without using membars
390 static void serialize_thread_states();
391
392 // Since we write to the serialize page from every thread, we
393 // want stores to be on unique cache lines whenever possible
394 // in order to minimize CPU cross talk. We pre-compute the
395 // amount to shift the thread* to make this offset unique to
396 // each thread.
397 static int get_serialize_page_shift_count() {
398 return SerializePageShiftCount;
399 }
400
401 static void set_serialize_page_mask(uintptr_t mask) {
402 _serialize_page_mask = mask;
403 }
404
405 static unsigned int get_serialize_page_mask() {
406 return _serialize_page_mask;
407 }
408
409 static void set_memory_serialize_page(address page);
410
411 static address get_memory_serialize_page() {
412 return (address)_mem_serialize_page;
413 }
414
415 static inline void write_memory_serialize_page(JavaThread *thread) {
416 uintptr_t page_offset = ((uintptr_t)thread >>
417 get_serialize_page_shift_count()) &
418 get_serialize_page_mask();
419 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
420 }
421
422 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
423 if (UseMembar) return false;
424 // Previously this function calculated the exact address of this
425 // thread's serialize page, and checked if the faulting address
426 // was equal. However, some platforms mask off faulting addresses
427 // to the page size, so now we just check that the address is
428 // within the page. This makes the thread argument unnecessary,
429 // but we retain the NULL check to preserve existing behaviour.
430 if (thread == NULL) return false;
431 address page = (address) _mem_serialize_page;
432 return addr >= page && addr < (page + os::vm_page_size());
433 }
434
435 static void block_on_serialize_page_trap();
436
437 // threads
438
439 enum ThreadType {
440 vm_thread,
441 cgc_thread, // Concurrent GC thread
442 pgc_thread, // Parallel GC thread
443 java_thread,
444 compiler_thread,
445 watcher_thread,
446 os_thread
447 };
448
449 static bool create_thread(Thread* thread,
450 ThreadType thr_type,
451 size_t stack_size = 0);
452 static bool create_main_thread(JavaThread* thread);
453 static bool create_attached_thread(JavaThread* thread);
454 static void pd_start_thread(Thread* thread);
455 static void start_thread(Thread* thread);
456
457 static void initialize_thread(Thread* thr);
458 static void free_thread(OSThread* osthread);
459
460 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
461 static intx current_thread_id();
462 static int current_process_id();
463 static int sleep(Thread* thread, jlong ms, bool interruptable);
464 // Short standalone OS sleep suitable for slow path spin loop.
465 // Ignores Thread.interrupt() (so keep it short).
466 // ms = 0, will sleep for the least amount of time allowed by the OS.
467 static void naked_short_sleep(jlong ms);
468 static void infinite_sleep(); // never returns, use with CAUTION
469 static void yield(); // Yields to all threads with same priority
470 enum YieldResult {
471 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
472 YIELD_NONEREADY = 0, // No other runnable/ready threads.
473 // platform-specific yield return immediately
474 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
475 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
476 // yield that can be used in lieu of blocking.
477 } ;
478 static YieldResult NakedYield () ;
479 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
480 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
481 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
482 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
483
484 static void interrupt(Thread* thread);
485 static bool is_interrupted(Thread* thread, bool clear_interrupted);
486
487 static int pd_self_suspend_thread(Thread* thread);
488
489 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
490 static frame fetch_frame_from_context(void* ucVoid);
491
492 static ExtendedPC get_thread_pc(Thread *thread);
493 static void breakpoint();
494
495 static address current_stack_pointer();
496 static address current_stack_base();
497 static size_t current_stack_size();
498
499 static void verify_stack_alignment() PRODUCT_RETURN;
500
501 static int message_box(const char* title, const char* message);
502 static char* do_you_want_to_debug(const char* message);
503
504 // run cmd in a separate process and return its exit code; or -1 on failures
505 static int fork_and_exec(char *cmd);
506
507 // os::exit() is merged with vm_exit()
508 // static void exit(int num);
509
510 // Terminate the VM, but don't exit the process
511 static void shutdown();
512
513 // Terminate with an error. Default is to generate a core file on platforms
514 // that support such things. This calls shutdown() and then aborts.
515 static void abort(bool dump_core = true);
516
517 // Die immediately, no exit hook, no abort hook, no cleanup.
518 static void die();
519
520 // File i/o operations
521 static const int default_file_open_flags();
522 static int open(const char *path, int oflag, int mode);
523 static FILE* open(int fd, const char* mode);
524 static int close(int fd);
525 static jlong lseek(int fd, jlong offset, int whence);
526 static char* native_path(char *path);
527 static int ftruncate(int fd, jlong length);
528 static int fsync(int fd);
529 static int available(int fd, jlong *bytes);
530
531 //File i/o operations
532
533 static size_t read(int fd, void *buf, unsigned int nBytes);
534 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
535 static size_t write(int fd, const void *buf, unsigned int nBytes);
536
537 // Reading directories.
538 static DIR* opendir(const char* dirname);
539 static int readdir_buf_size(const char *path);
540 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
541 static int closedir(DIR* dirp);
542
543 // Dynamic library extension
544 static const char* dll_file_extension();
545
546 static const char* get_temp_directory();
547 static const char* get_current_directory(char *buf, size_t buflen);
548
549 // Builds a platform-specific full library path given a ld path and lib name
550 // Returns true if buffer contains full path to existing file, false otherwise
551 static bool dll_build_name(char* buffer, size_t size,
552 const char* pathname, const char* fname);
553
554 // Symbol lookup, find nearest function name; basically it implements
555 // dladdr() for all platforms. Name of the nearest function is copied
556 // to buf. Distance from its base address is optionally returned as offset.
557 // If function name is not found, buf[0] is set to '\0' and offset is
558 // set to -1 (if offset is non-NULL).
559 static bool dll_address_to_function_name(address addr, char* buf,
560 int buflen, int* offset);
561
562 // Locate DLL/DSO. On success, full path of the library is copied to
563 // buf, and offset is optionally set to be the distance between addr
564 // and the library's base address. On failure, buf[0] is set to '\0'
565 // and offset is set to -1 (if offset is non-NULL).
566 static bool dll_address_to_library_name(address addr, char* buf,
567 int buflen, int* offset);
568
569 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
570 static bool address_is_in_vm(address addr);
571
572 // Loads .dll/.so and
573 // in case of error it checks if .dll/.so was built for the
574 // same architecture as Hotspot is running on
575 static void* dll_load(const char *name, char *ebuf, int ebuflen);
576
577 // lookup symbol in a shared library
578 static void* dll_lookup(void* handle, const char* name);
579
580 // Unload library
581 static void dll_unload(void *lib);
582
583 // Return the handle of this process
584 static void* get_default_process_handle();
585
586 // Check for static linked agent library
587 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
588 size_t syms_len);
589
590 // Find agent entry point
591 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
592 const char *syms[], size_t syms_len);
593
594 // Print out system information; they are called by fatal error handler.
595 // Output format may be different on different platforms.
596 static void print_os_info(outputStream* st);
597 static void print_os_info_brief(outputStream* st);
598 static void print_cpu_info(outputStream* st);
599 static void pd_print_cpu_info(outputStream* st);
600 static void print_memory_info(outputStream* st);
601 static void print_dll_info(outputStream* st);
602 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
603 static void print_context(outputStream* st, void* context);
604 static void print_register_info(outputStream* st, void* context);
605 static void print_siginfo(outputStream* st, void* siginfo);
606 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
607 static void print_date_and_time(outputStream* st);
608
609 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
610 static size_t lasterror(char *buf, size_t len);
611 static int get_last_error();
612
613 // Determines whether the calling process is being debugged by a user-mode debugger.
614 static bool is_debugger_attached();
615
616 // wait for a key press if PauseAtExit is set
617 static void wait_for_keypress_at_exit(void);
618
619 // The following two functions are used by fatal error handler to trace
620 // native (C) frames. They are not part of frame.hpp/frame.cpp because
621 // frame.hpp/cpp assume thread is JavaThread, and also because different
622 // OS/compiler may have different convention or provide different API to
623 // walk C frames.
624 //
625 // We don't attempt to become a debugger, so we only follow frames if that
626 // does not require a lookup in the unwind table, which is part of the binary
627 // file but may be unsafe to read after a fatal error. So on x86, we can
628 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
629 // possible to walk C stack without having the unwind table.
630 static bool is_first_C_frame(frame *fr);
631 static frame get_sender_for_C_frame(frame *fr);
632
633 // return current frame. pc() and sp() are set to NULL on failure.
634 static frame current_frame();
635
636 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
637
638 // returns a string to describe the exception/signal;
639 // returns NULL if exception_code is not an OS exception/signal.
640 static const char* exception_name(int exception_code, char* buf, size_t buflen);
641
642 // Returns native Java library, loads if necessary
643 static void* native_java_library();
644
645 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
646 static void jvm_path(char *buf, jint buflen);
647
648 // Returns true if we are running in a headless jre.
649 static bool is_headless_jre();
650
651 // JNI names
652 static void print_jni_name_prefix_on(outputStream* st, int args_size);
653 static void print_jni_name_suffix_on(outputStream* st, int args_size);
654
655 // File conventions
656 static const char* file_separator();
657 static const char* line_separator();
658 static const char* path_separator();
659
660 // Init os specific system properties values
661 static void init_system_properties_values();
662
663 // IO operations, non-JVM_ version.
664 static int stat(const char* path, struct stat* sbuf);
665 static bool dir_is_empty(const char* path);
666
667 // IO operations on binary files
668 static int create_binary_file(const char* path, bool rewrite_existing);
669 static jlong current_file_offset(int fd);
670 static jlong seek_to_file_offset(int fd, jlong offset);
671
672 // Thread Local Storage
673 static int allocate_thread_local_storage();
674 static void thread_local_storage_at_put(int index, void* value);
675 static void* thread_local_storage_at(int index);
676 static void free_thread_local_storage(int index);
677
678 // Retrieve native stack frames.
679 // Parameter:
680 // stack: an array to storage stack pointers.
681 // frames: size of above array.
682 // toSkip: number of stack frames to skip at the beginning.
683 // Return: number of stack frames captured.
684 static int get_native_stack(address* stack, int size, int toSkip = 0);
685
686 // General allocation (must be MT-safe)
687 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
688 static void* malloc (size_t size, MEMFLAGS flags);
689 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
690 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
691
692 static void free (void *memblock, MEMFLAGS flags = mtNone);
693 static bool check_heap(bool force = false); // verify C heap integrity
694 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
695
696 #ifndef PRODUCT
697 static julong num_mallocs; // # of calls to malloc/realloc
698 static julong alloc_bytes; // # of bytes allocated
699 static julong num_frees; // # of calls to free
700 static julong free_bytes; // # of bytes freed
701 #endif
702
703 // SocketInterface (ex HPI SocketInterface )
704 static int socket(int domain, int type, int protocol);
705 static int socket_close(int fd);
706 static int socket_shutdown(int fd, int howto);
707 static int recv(int fd, char* buf, size_t nBytes, uint flags);
708 static int send(int fd, char* buf, size_t nBytes, uint flags);
709 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
710 static int timeout(int fd, long timeout);
711 static int listen(int fd, int count);
712 static int connect(int fd, struct sockaddr* him, socklen_t len);
713 static int bind(int fd, struct sockaddr* him, socklen_t len);
714 static int accept(int fd, struct sockaddr* him, socklen_t* len);
715 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
716 struct sockaddr* from, socklen_t* fromlen);
717 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
718 static int sendto(int fd, char* buf, size_t len, uint flags,
719 struct sockaddr* to, socklen_t tolen);
720 static int socket_available(int fd, jint* pbytes);
721
722 static int get_sock_opt(int fd, int level, int optname,
723 char* optval, socklen_t* optlen);
724 static int set_sock_opt(int fd, int level, int optname,
725 const char* optval, socklen_t optlen);
726 static int get_host_name(char* name, int namelen);
727
728 static struct hostent* get_host_by_name(char* name);
729
730 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
731 static void signal_init();
732 static void signal_init_pd();
733 static void signal_notify(int signal_number);
734 static void* signal(int signal_number, void* handler);
735 static void signal_raise(int signal_number);
736 static int signal_wait();
737 static int signal_lookup();
738 static void* user_handler();
739 static void terminate_signal_thread();
740 static int sigexitnum_pd();
741
742 // random number generation
743 static long random(); // return 32bit pseudorandom number
744 static void init_random(long initval); // initialize random sequence
745
746 // Structured OS Exception support
747 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
748
749 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
750 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
751
752 // Get the default path to the core file
753 // Returns the length of the string
754 static int get_core_path(char* buffer, size_t bufferSize);
755
756 // JVMTI & JVM monitoring and management support
757 // The thread_cpu_time() and current_thread_cpu_time() are only
758 // supported if is_thread_cpu_time_supported() returns true.
759 // They are not supported on Solaris T1.
760
761 // Thread CPU Time - return the fast estimate on a platform
762 // On Solaris - call gethrvtime (fast) - user time only
763 // On Linux - fast clock_gettime where available - user+sys
764 // - otherwise: very slow /proc fs - user+sys
765 // On Windows - GetThreadTimes - user+sys
766 static jlong current_thread_cpu_time();
767 static jlong thread_cpu_time(Thread* t);
768
769 // Thread CPU Time with user_sys_cpu_time parameter.
770 //
771 // If user_sys_cpu_time is true, user+sys time is returned.
772 // Otherwise, only user time is returned
773 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
774 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
775
776 // Return a bunch of info about the timers.
777 // Note that the returned info for these two functions may be different
778 // on some platforms
779 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
780 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
781
782 static bool is_thread_cpu_time_supported();
783
784 // System loadavg support. Returns -1 if load average cannot be obtained.
785 static int loadavg(double loadavg[], int nelem);
786
787 // Hook for os specific jvm options that we don't want to abort on seeing
788 static bool obsolete_option(const JavaVMOption *option);
789
790 // Extensions
791 #include "runtime/os_ext.hpp"
792
793 public:
794 class CrashProtectionCallback : public StackObj {
795 public:
796 virtual void call() = 0;
797 };
798
799 // Platform dependent stuff
800 #ifdef TARGET_OS_FAMILY_linux
801 # include "os_linux.hpp"
802 # include "os_posix.hpp"
803 #endif
804 #ifdef TARGET_OS_FAMILY_solaris
805 # include "os_solaris.hpp"
806 # include "os_posix.hpp"
807 #endif
808 #ifdef TARGET_OS_FAMILY_windows
809 # include "os_windows.hpp"
810 #endif
811 #ifdef TARGET_OS_FAMILY_aix
812 # include "os_aix.hpp"
813 # include "os_posix.hpp"
814 #endif
815 #ifdef TARGET_OS_FAMILY_bsd
816 # include "os_posix.hpp"
817 # include "os_bsd.hpp"
818 #endif
819 #ifdef TARGET_OS_ARCH_linux_x86
820 # include "os_linux_x86.hpp"
821 #endif
822 #ifdef TARGET_OS_ARCH_linux_sparc
823 # include "os_linux_sparc.hpp"
824 #endif
825 #ifdef TARGET_OS_ARCH_linux_zero
826 # include "os_linux_zero.hpp"
827 #endif
828 #ifdef TARGET_OS_ARCH_solaris_x86
829 # include "os_solaris_x86.hpp"
830 #endif
831 #ifdef TARGET_OS_ARCH_solaris_sparc
832 # include "os_solaris_sparc.hpp"
833 #endif
834 #ifdef TARGET_OS_ARCH_windows_x86
835 # include "os_windows_x86.hpp"
836 #endif
837 #ifdef TARGET_OS_ARCH_linux_arm
838 # include "os_linux_arm.hpp"
839 #endif
840 #ifdef TARGET_OS_ARCH_linux_ppc
841 # include "os_linux_ppc.hpp"
842 #endif
843 #ifdef TARGET_OS_ARCH_aix_ppc
844 # include "os_aix_ppc.hpp"
845 #endif
846 #ifdef TARGET_OS_ARCH_bsd_x86
847 # include "os_bsd_x86.hpp"
848 #endif
849 #ifdef TARGET_OS_ARCH_bsd_zero
850 # include "os_bsd_zero.hpp"
851 #endif
852
853 public:
854 #ifndef PLATFORM_PRINT_NATIVE_STACK
855 // No platform-specific code for printing the native stack.
856 static bool platform_print_native_stack(outputStream* st, void* context,
857 char *buf, int buf_size) {
858 return false;
859 }
860 #endif
861
862 // debugging support (mostly used by debug.cpp but also fatal error handler)
863 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
864
865 static bool dont_yield(); // when true, JVM_Yield() is nop
866 static void print_statistics();
867
868 // Thread priority helpers (implemented in OS-specific part)
869 static OSReturn set_native_priority(Thread* thread, int native_prio);
870 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
871 static int java_to_os_priority[CriticalPriority + 1];
872 // Hint to the underlying OS that a task switch would not be good.
873 // Void return because it's a hint and can fail.
874 static void hint_no_preempt();
875
876 // Used at creation if requested by the diagnostic flag PauseAtStartup.
877 // Causes the VM to wait until an external stimulus has been applied
878 // (for Unix, that stimulus is a signal, for Windows, an external
879 // ResumeThread call)
880 static void pause();
881
882 // Builds a platform dependent Agent_OnLoad_<libname> function name
883 // which is used to find statically linked in agents.
884 static char* build_agent_function_name(const char *sym, const char *cname,
885 bool is_absolute_path);
886
887 class SuspendedThreadTaskContext {
888 public:
889 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
890 Thread* thread() const { return _thread; }
891 void* ucontext() const { return _ucontext; }
892 private:
893 Thread* _thread;
894 void* _ucontext;
895 };
896
897 class SuspendedThreadTask {
898 public:
899 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
900 virtual ~SuspendedThreadTask() {}
901 void run();
902 bool is_done() { return _done; }
903 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
904 protected:
905 private:
906 void internal_do_task();
907 Thread* _thread;
908 bool _done;
909 };
910
911 #ifndef TARGET_OS_FAMILY_windows
912 // Suspend/resume support
913 // Protocol:
914 //
915 // a thread starts in SR_RUNNING
916 //
917 // SR_RUNNING can go to
918 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
919 // SR_SUSPEND_REQUEST can go to
920 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
921 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
922 // SR_SUSPENDED can go to
923 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
924 // SR_WAKEUP_REQUEST can go to
925 // * SR_RUNNING when the stopped thread receives the signal
926 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
927 class SuspendResume {
928 public:
929 enum State {
930 SR_RUNNING,
931 SR_SUSPEND_REQUEST,
932 SR_SUSPENDED,
933 SR_WAKEUP_REQUEST
934 };
935
936 private:
937 volatile State _state;
938
939 private:
940 /* try to switch state from state "from" to state "to"
941 * returns the state set after the method is complete
942 */
943 State switch_state(State from, State to);
944
945 public:
946 SuspendResume() : _state(SR_RUNNING) { }
947
948 State state() const { return _state; }
949
950 State request_suspend() {
951 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
952 }
953
954 State cancel_suspend() {
955 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
956 }
957
958 State suspended() {
959 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
960 }
961
962 State request_wakeup() {
963 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
964 }
965
966 State running() {
967 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
968 }
969
970 bool is_running() const {
971 return _state == SR_RUNNING;
972 }
973
974 bool is_suspend_request() const {
975 return _state == SR_SUSPEND_REQUEST;
976 }
977
978 bool is_suspended() const {
979 return _state == SR_SUSPENDED;
980 }
981 };
982 #endif
983
984
985 protected:
986 static long _rand_seed; // seed for random number generator
987 static int _processor_count; // number of processors
988 static int _initial_active_processor_count; // number of active processors during initialization.
989
990 static char* format_boot_path(const char* format_string,
991 const char* home,
992 int home_len,
993 char fileSep,
994 char pathSep);
995 static bool set_boot_path(char fileSep, char pathSep);
996 static char** split_path(const char* path, int* n);
997
998 };
999
1000 // Note that "PAUSE" is almost always used with synchronization
1001 // so arguably we should provide Atomic::SpinPause() instead
1002 // of the global SpinPause() with C linkage.
1003 // It'd also be eligible for inlining on many platforms.
1004
1005 extern "C" int SpinPause();
1006
1007 #endif // SHARE_VM_RUNTIME_OS_HPP